Boiler tube cleaning apparatus



Nov. 28, 1967 D. G. MASTERS ET AL 3,354,490

BOILER TUBE CLEANING APPARATUS. I

Filed June 15, 1964 2 Sheets-Sheet 1 4 IIIIIIIII'IIIHIIII IlllllllllflllllllllfllllllllllllllllllllllllllllIlllllllllllllllllllllllllllll"IIIlllllllllllllIII|llIllllllllllllllflllllll zwwwwW\ H v? J S v.

AY/VF C. WORSTZLL Don CnMasi'ers INVENTOR.

1967 D. G. MASTERS ET AL 3,354,490

BOILER TUBE CLEANING APPARATUS Filed June 15. 1964 2 Sheets-Sheet 2 WAy/vE c. WORSTEZ L Don 6. Ma 5 +ers INVENTOR.

3 ,flM/W 7 I Hfg S.

United States Patent O 3,354,490 BOILER TUBE CLEANING APPARATUS Don G.Masters and Wayne C. Worstell, Portland, reg.,

assignors to Power Tube, Inc., Portland, 0reg., a corporation of OregonFiled June 15, 1964, Ser. No. 374,976 8 Claims. (Cl. 15-1041) Thisinvention relates to apparatus for cleaning the tubes of a boiler.

A common form of boiler includes multiple fire tubes disposed side byside and parallel to each other in the boiler, which periodically mustbe cleaned of soot and scale in order to maintain the efficiency of theboiler. Studies have shown that the presence of only a smallaccumulation of scale, ash or soot on the walls of boiler tubes willresult in a considerable loss of efficiency. This invention morespecifically concerns cleaning apparatus which features a shaft having aboiler tube cleaning instrument mounted on one end thereof, and anejector which may be operated to thrust the shaft inside a tube so thatthe cleaning instrument thereon moves along the inside ofthe tube withsuch instrument then scraping and brushing the tube.

A general object of this invention is to provide cleaning apparatus ofthis description which includes a poweroperated ejector unit forthrusting a shaft forwardly into a boiler tube, and novel means mountingsuch unit whereby the same is supported in such a manner as to be fullybraced against the reaction forces set up in the unit when the'unit isoperated, the mounting for the unit at the 'same time enabling the unitto be readily moved to place 'it in proper position for cleaniingsuccessive ones of a plurality of tubes.

' More specifically, an object of this invention is to provide tubecleaning apparatus, which includes tracks extending horizontallyadjacent the top and bottom of a boiler, and an upright standardextending between these tracks and anchored adjacent its ends on thetracks by means accommodating travel of the standard in a directionparalleling the tracks, such standard including a vertical-1y movablecarriage upon which is mounted the ejector unit previously generallydescribed.

Included in the objects of this invention is the provision of a novelconstruction whereby the standard may be released from the meansanchoring the lower end thereof, to enable the base of the standard tobe swung out when desired, thus to produce greater freedom of movementin the standard, whereby when the same is shifted laterally it may bemoved to one side of obstructions.

Yet another object is to provide novel mechanism for ejecting a shafthaving a cleaning instrumentality mounted thereon toward and thence intoa boiler tube.

A further object is to provide cleaning apparatus as above describedfeaturing a novel shaft which is flexible and at the same timecompression and tension transmitting. The flexibility in the shaft isimportant in permitting a reduction in the space required to operate thecleaning apparatus.

Other objects and advantages are attained by the invention, and the sameis described hereinbelow in conjunction with the accompanying drawings,wherein FIG. 1 is a side elevation of apparatus constructed according tothis invention, showing portions of a boiler and with cleaning apparatusmounted in front thereof;

FIG. 2 is an end elevation of the apparatus illustrated in FIG. I;

"ice

FIG. 3 is a cross sectional View, taken generally along the line 3--3 inFIG. 2, and on an enlarged scale, illustrating details of an ejectorunit employed to thrust a shaft into a tube for cleaning purposes; and

FIG. 4 is an enlarged view of portions of a shaft used in the apparatusfor mounting a tube cleaning instrument.

Referring now to the drawings, in FIGS. 1 and 2 a boiler 10 isindicated, which has mounted therewithin a bank of fire tubes, indicatedindividually at 12. A shell 14 surrounds these tubes, and as is commonwith boilers, doors 16 may be provided that normally close off the endof the boiler and that are swung apart on hinges 18 to open up the endof the boiler for cleaning purposes. Tubes 12 within the boiler areshown extending through a plate 20 mounting the tubes in place. Thetubes at opposite ends of the boiler have open ends.

In a given installation, it is not uncommon to find a number of theboilers of the type described mounted side by side. With the apparatusof the invention a plurality of such boilers may be serviced by cleaningthe fire tubes of each.

As contemplated herein, a stationary framework is provided, which ismounted adjacent the ends of a series of boilers of the type described.This framework supports a power-driven ejector unit which is actuated toproduce cleaningof a tube. The framework accommodates movement of theejector unit in a direction extending transversely of the boilers,whereby successive vertical rows of tubes may be cleaned using the sameejector unit. In FIGS. 1 and 2, this framework is indicated generally at26.

Considering details of framework 26, at 30 there is illustrated an uppertrack, comprising a rail which extends transversely of boiler 10 andwhich is mounted slightly in front of one end of the boiler. Secured, asby welding, to the shell of boiler 10 is a bracket structure 34, whichis effective to hold rail 30 securely in a fixed position. While rail 30has been shown broken off, in a multiple boiler installation, the railextends as shown across the ends of all boilers.

Paralleling rail 30, and shown extending transversely of the boileradjacent the bottom of the boiler is another track 36. This track alsomay comprise a rail, which is mounted in a fixed position, by means ofbrackets 40 secured to the boiler adjacent the base of the boiler.

According to this invention, a power-driven ejector unit, showngenerally at 42, is actuated to thrust forwardly a shaft 43 having acleaning instrument mounted on one end, shown generally at 44, with thecleaning instrument then moving down the interior of a fire tube.

'This produces reaction forces in the ejector unit, whereby the sametends to be thrown backwardly away 'from the boiler and the tube beingcleaned. The upper and lower tracks described provide a mounting forthis ejector unit accommodating movement of the ejector unit in atransverse direction, while ruggedly bracing the unit so as to preventthe same from being thrown backwardly when the same is operated.

Further describing the mounting for the ejector unit, an uprightstandard or rail is shown at 46. Mounting the upper end of standard 46on rail 30 is a trolley or traveling anchoring means 48, including abody 50 with flanged wheels 52 journaled thereon. A sleeve or socket 56having standard 46 extending upwardly therethrough is joined to body 50.A hand-wheel adjusted screw 58 mounted on this sleeve may be tightenedto clamp the standard in a given position within the sleeve. In theconstruction described, the top edge of rail 30 supports the weight ofthe apparatus, and flanges 52a of wheels 52, by engaging the back sideof rail 30, i.e., the side facing the boilers, function to prevent thetrolley from being forced to the right in FIG. 1, or forwardly of theboiler and off the track.

The bottom end of standard 46 is mounted on the lower track throughtraveling anchoring means or guide 60. This guide includes a plate 62that is slidable along the back side of rail 36, and in front of thisplate a channel-shaped part 64 which fits about standard 46. Pivoted tochannel-shaped part 64 is a gate 66 (pivoted at 68), which is detachablyjoined to part 64 in back of it by a hand-wheel adjusted screw '70.Thus, by loosening the hand-wheel screw and swinging the gate outwardly,the base of standard 46 is released. The base of the standard when it isreleased, may be swung outwardly from the boiler and rail 36, with thestandard pivoting above an axis generally corresponding to the top ofrail 32 (trolley 48 being tiltable to some extent on the top of rail32). This is an important feature, since in boiler installations,furnaces and other equipment are often found in front of the boilers,and these would offer an impassable obstruction to a standard whose basewas constrained to movement along rail 36. By providing the gate and'because the standard is swingable as described, the standard is easilyshifted past such an obstruction.

Power-driven ejector unit 42 is mounted on a carriage 72 mounted for upand down movement on the standard. At 74 is a hand-wheel adjusted screw,which may be tightened to secure the carriage in place, in differentpositions on the standard. Also mounted on the carriage is an electricmotor 76. Motor 76 and unit 42 are on opposite sides of a plate 78 whichis part of the carriage.

Referring now to FIG. 3, unit 42 comprises a housing 80 having journaledtherewithin oppositely disposed grooved wheels 82, 84, also referred toas clamping wheels. Wheel 82 constitutes a power-driven wheel, and

is connected directly to the output shaft of motor 76..

Wheel 84 is a pressure-applying wheel, and is journaled on a member 86which is pivoted at 88 within the housing. A hand-wheel adjusted nut 90is screwed onto a stud 92, and the latter is anchored at 94 within thehousing. Encircling stud 92 is a spring 96, interposed between member 86and hand-wheel adjusted nut 90. Spring 96 exerts a bias on member 86,and it will be obvious that by tightening the hand-wheel adjusted nut, agreater compressive force is exerted by the spring on member 86, wherebywheel 84 is urged with greater force toward wheel 82.

Shaft 43 which has cleaning instrument 44 mounted thereon, and referringto FIG. 4, comprises a spring steel,

helically wound, hollow body 102. Within body 102 is a cable 104. Thecable extends along the inside of the spring steel hollow body, and issecured to the. body at the ends of the body by an anchor connectionsuch as the one shown at 106 in FIG. 4. With this construction the shaftis flexible, since the windings of the hollow body may flex with respectto each other and at the same time, the shaft constitutes a thrusttransmitting member, in that when the same is thrust forwardly it willtransfer this thrust to the cleaning instrument mounted at its forwardend. Further, the shaft is a tension-transmitting member, and on beingwithdrawn will not stretch out because of the inclusion of cable 104within it which is nonextensible.

Shaft 43 is moved forwardly into a tube and withdrawn from the tube bythe power-driven ejector unit, more specifically, by the action ofwheels 82, 84 within the unit which engage the shaft on opposite sides.As can be seen in FIG. 3, the shaft enters housing 80 through afunnel-shaped portion 108 of the casing. After passing between wheels82, 84, the shaft extends through a nozzle part or shaft guide 110,which is pivoted within the housing at 112.

The nozzle part is included in order to afford control over thedirection in which the shaft is fed out from the ejector unit. It willbe noted than an ear 114 is provided which projects upwardly from thenozzle part, and that a stud 116 anchored to the housing at 118 extendsthrough a slot in ear 114. A compression spring 120 encircles the stud,and a hand-wheel adjusted nut is shown at 122 which is screwed onto stud116. On tightening the hand-wheel adjusted nut, the nozzle part swingsupwardly, and on loosening the nut, the nozzle part swings downwardly,spring 120 functioning to keep ear 114 tight against nut 122. With thenozzle part swung upwardly, the shaft where it extends out from thenozzle part is directed upwardly, and on swinging the part downwardly,the shaft is directed downwardly.

As can be seen in FIG. 1, cleaning instrument 44 includes a scraper 124,and a brush 126. These are mounted on an end of the shaft through afitting 128. The opposite end of the shaft may be connected, as by chain130, to an ear 132 which extends out from the casing of ejector unit 42.

Completing the description of the invention, to raise and lower carriage72 and the ejector unit, a winch 134 and a cable 136 is provided. Thelower end of the cable is wrapped around the drum of the winch, and fromthence the cable passes upwardly over a pulley 138 and downwardly to aconnection 140 with plate 78 of the carriage. From this it should beobvious that on proper actuation of the Winch, the carriage may beshifted either upwardly or downwardly on the standard.

Explaining how the apparatus may be used to clean the tubes in a boiler,the carriage may first be placed at an elevation such that the forwardend of the shaft projecting from ejector unit 42 and instrument 44 areat substantially the same level as a bank of tubes within the boiler.Electric motor 76, which is reversible, is then operated, first toadvance the shaft into a tube, with the tube then being cleaned. Anoperator, as by noting the extent to which the shaft has traveled into atube, determines when instrument 44 has traveled the length of the tube.The operator may then reverse motor 76, whereby the shaft and instrument44 are withdrawn.

An operator may then easily shift the standard, using the trolleysupporting it at the top, and the guide at the bottom, to place theshaft in front of a tube next to the tube just cleaned. The cleaningoperation may then be repeated. On cleaning the tubes in a given level,the winch may be operated to either lower or raise the carriage,depending upon which level of tubes is to be cleaned next. The operationmay then be repeated.

Where it is desired to make small adjustments in the direction in whichthe shaft isthrust forwardly from the ejector unit, such can be done byproper manipulation of hand-wheel nut 122. This feature is especiallyimportant when cleaning a level of tubes that otherwise would be toohigh or too low to be reachable with unit 42 with a nozzle part pointingstraight ahead.

An important part of the invention is that duringmovement of the shaftinto and along a dirty tube, the ejector unit is ruggedly braced toresist reaction forces set up therein. This is because both top andbottom positions. of the standard are held securely from displacementlaterally of the tracks. The structure is relatively compact, and asalready noted, the standard may be released adjacent its bottom from thelower guide, to accommodate its being swung out and around obstructionssuch as. furnaces and the like.

Because the shaft is flexible, a great deal of space to provideclearance for the shaft when the same is retracted is not needed.

While an embodiment of the invention has been described, changes andvariations are" possible without departing therefrom. It is desired tocover all modifications and variations as would be apparent to oneskilled in the art, and that come within the scope of the appendedclaims.

It is claimed and desired to secure by Letters Patent:

1. Apparatus for'clea'ning tubes in a' boiler comprising upper and lowersubstantially horizontal tracks mounted in a stationary positionadjacent the top and bottom of the boiler, respectively, and extendingtransversely of the tubes,

each of said tracks including an elongated rail having an upper edge,and a back side facing one set of ends of the tubes,

an upright standard substantially spanning the space between said rails,f

a first traveling anchoring device supported by and riding on said uppertrack including means engaging said back side and upper edge of the railin the upper track and attaching means securing the upper end of saidstandard to said first anchoring device with the device movable alongsaid upper track while secured to the standard,

a second traveling anchoring device supported by and riding on saidlower track including means engaging the back side of the rail in thelower track and attaching means securing the lower end of said standardto said second device with the second device movable along said lowertrack,

an ejector unit including power-operated means for thrusting a boilertube cleaning instrument into and along the length of a boiler tube, and

means mounting said ejector unit on said standard with the unit entirelysupported by the standard accommodating positioning of the unit atvarious positions on the standard.

2. The apparatus of claim 1, wherein the attaching means securing thelower end of the standard to said second traveling anchoring deviceincludes adjustable means accommodating release of the standard wherebythe standards lower end may be swung laterally and forwardly of thebottom track and said first traveling anchoring device is shiftable onsaid upper track while riding on the track to accommodate such lateralswinging of the standard which is attached to the device.

3. Apparatus for cleaning tubes in a boiler comprising upper and lowersubstantially horizontal tracks mounted in a stationary positionadjacent the top and bottom of the boiler, respectively, and extendingtransversely of the tubes,

an upright standard substantially spanning the space between saidtracks,

a traveling anchoring device supported by and riding on said upper trackand attaching means securing the upper end of said standard to saiddevice with the device movable along said upper track while secured tothe standard,

said last-mentioned device being swingable about an axis substantiallyparalleling the track,

another traveling anchoring device supported by and riding on said lowertrack and attaching means securing the lower end of said standard tosaid other device with the device movable along said lower track,

said attaching means for said other anchoring device including anopenable gate which when opened releases the standard adjacent its lowerend whereby its lower end may be swung laterally and forwardly with thestandard then pivoting about the upper anchoring means,

an ejector unit including power-operated means for thrusting a boilertube cleaning instrument into and along the length of a tube, and

means mounting said unit on the standard with the unit entirely suportedby the standard.

4. In boiler tube cleaning apparatus,

an upright standard adapted to be mounted in front of an end of aboiler,

an upper and a lower horizontal track adapted to be mounted in front ofthe boiler, first and second anchoring devices-supported by and ridingon said upper and lower tracks, respectively, attaching means securingthe upper end of said standard to said first device with the devicemovable along said upper track while secured to the standard andattaching means securing the lower end of said standard to said seconddevice with the device movable along said lower track while secured tothe standard,

a carriage mounted on the standard for movement up and down thereon, v Hp means mounted on the standard operable when actuated to produce suchup and down movement, and

an ejector unit entirely supported on said carriage for thrusting ashaft into a boiler tube and along the length thereof,

said unit including a shaft guide constructed to have a shaft movelengthwise therethrough and spaced laterally to one side of saidstandard, and poweroperated means for advancing a shaft through saidshaft guide.

5. The apparatus of claim 4, wherein a flexible shaft extends throughthe shaft guide, and the shaft guide comprises an elongated nozzle, andsaid nozzle has an end which is movable up and down to change thedirection along which a shaft travels on passing through the nozzle.

6. In apparatus for cleaning the tubes of a boiler,

an elongated flexible shaft,

a power-operated unit adapted to be mounted in front of one set of endsof the tubes in the boiler,

said power-operated unit including a housing,

an elongated shaft guide receiving said shaft and constructed to havesaid shaft moved lengthwise therethlrjough with guiding of said shafttoward a boiler til 6,

means pivotally mounting one end of the shaft guide in said housing,

means operatively interposed between the housing and shaft guide forswinging the shaft guide about its pivot connection with the housing,and

power-operated means mounted in the housing adjacent said one end ofsaid shaft guide clamping onto said shaft for forcing the same throughsaid guide in either of opposite directions.

7. The apparatus of claim 6, wherein said poweroperated means comprisesa pair of oppositely disposed clamping wheels journaled in said housing,motor means connected to one of the wheels for rotating the same underpower, and means operatively connected to the other wheel exerting abias on the wheel whereby the two wheels are urged together thus toclamp onto a shaft, the latter means being adjustable to change the biasexerted thereon whereby the clamping pressure exerted by the wheels maybe changed.

3. Apparatus for cleaning tubes in a boiler comprising upper and lowersubstantially horizontal tracks mounted in a stationary positionadjacent the top and bottom of the boiler, respectively, and extendingtransversely of the tubes;

an upright standard substantially spanning the space between saidtracks;

a traveling anchoring device movably supported by and rideable on saidupper track, and attaching means securing the upper end of said standardto the device with the standard depending from the device and movablywith the device along said track while secured to the device;

a traveling anchor device supported by and riding on said lower track,and means mounting the lower end of said standard on saidsecond-mentioned device movable along said lower track while having thestandard mounted on it;

an ejector unit including power-operated means for thrusting a boilertube cleaning instrument into and along the length of a boiler tube; and

7 means. mounting said ejector unit on said standard,

with the unit entirely supported by the standard, accommodatingpositioning of the. unit at various positions on the standard with said,unit held stationary in said positions.

References Cited UNITED STATES PATENTS 690,878 1/1902 'Roan 15104.1

Casaday 15104.1 Miller. Silverrnan 15--104.3 OBrien 15-1043 X Cheadle15-104.2

FOREIGN PATENTS 4/1960 Great Britain.

Switzerland.

4/1902 Forsyt-h et a1. 15-1041 10 ROBERT w. MICHELL, Primary Examiner.

8. APPARATUS FOR CLEANING TUBES IN A BOILER COMPRISING UPPER AND LOWERSUBSTANTIALLY HORIZONTAL TRACKS MOUNTED IN A STATIONARY POSITIONADJACENT THE TOP AND BOTTOM OF THE BOILER, RESPECTIVELY, AND EXTENDINGTRANSVERSELY OF THE TUBES; AN UPRIGHT STANDARD SUBSTANTIALLY SPANNINGTHE SPACE BETWEEN SAID TRACKS; A TRAVELING ANCHORING DEVICE MOVABLYSUPPORTED BY AND RIDEABLE ON SAID UPPER TRACK, AND ATTACHING MEANSSECURING THE UPPER END OF SAID STANDARD TO THE DEVICE WITH THE STANDARDDEPENDING FROM THE DEVICE AND MOVABLY WITH THE DEVICE ALONG SAID TRACKWHILE SECURED TO THE DEVICE; A TRAVELING ANCHOR DEVICE SUPPORTED BY ANDRIDING ON SAID LOWER TRACK, AND MEANS MOUNTING THE LOWER END OF SAIDSTANDARD ON SAID SECOND-MENTIONED DEVICE MOVABLE ALONG SAID LOWER TRACKWHILE HAVING THE STANDARD MOUNTED ON IT; AN EJECTOR UNIT INCLUDINGPOWER-OPERATED MEANS FOR THRUSTING A BOILER TUBE CLEANING INSTRUMENTINTO AND ALONG THE LENGTH OF A BOILER TUBE; AND MEANS MOUNTING SAIDEJECTOR UNIT ON SAID STANDARD, WITH THE UNIT ENTIRELY SUPPORTED BY THESTANDARD, ACCOMMODATING POSITIONING OF THE UNIT AT VARIOUS POSITIONS ONTHE STANDARD WITH SAID UNIT HELD STATIONARY IN SAID POSITIONS.